(1) Field of the Invention
The present invention relates to a device for supporting a medical equipment such as an operation microscope, a surgeon's knife using laser beam (laser mes), an X-ray machine, etc., and more particularly, it relates to a braking system of a polyarticulated arm adapted for supporting the medical equipment at one end thereof and attached to a support pole of the supporting device at the other end while being designed to be rotatable or pivotable.
(2) Description of the Prior Art
In the medical equipment such as the operation microscope, the laser mes, the X-ray machine and the like which are used to treat, examine or insepct diseased portions by optical or electronic means, it is necessary to locate the equipment at a place where the diseased portions are conveniently or best observed and the treatment or operation is not interrupted by the equipment. For this purpose, there have been already put into practical use the medical equipment supporting devices which can support the medical equipment at an arbitrary spatial position by the construction that the polyarticulated arm is rotatably and pivotably supported at one end thereof on a support pole of a floor stand type or a ceiling suspension type, and the medical equipment is attached to the other end of the polyarticulated arm.
In the conventional supporting devices of this type, an arm rotary shaft at each joint of the polyarticulated arm is clamped by means of a locking screw so that the medical equipment may be fixed at an arbitrary spatial position. Thus, when a number of the joints of the polyarticulated arm is increased to assure a large latitude in movement and enable fine adjustment, the number of the locking screws are proportionally increased. Consequently, the operation becomes extremely troublesome because a number of these locking screws must be loosened or tightened every time the medical equipment is intended or required to be moved to another spatial position. Particularly, since the operation microscope, for instance, the operation microscope for use in neuro surgery or otorhinolaryngological surgery is required to be frequently adjusted in the spatial position during operation because the diseased portions undergoing the operation are extended over a relatively wide range in three dimension and the observation must be made in an extremely many directions. Further, in case an operator moves the microscope, the locking screws must always be maintained in a sterilized state, which is a very hard task. If the locking screws are not sterilized, the operator or his operation assistant is not allowed to touch them and another person's help is necessary for moving the microscope.
As an example of the prior art eliminating the above drawbacks, there is a supporting device disclosed in Japanese Patent Application Laid Open No. 48-40450. According to this supporting device, the polyarticulated arm is prevented to be rotatively moved by supplying a current to an electromagnet installed in each joint portion of the polyarticulated arm (three-dimensionally adjustable Carden link mechanism), and the arm comes to be rotatively moved by cutting off the electric power supply to the electromagnet through the operators switching-off action, whereby the medical equipment can be moved and stopped at a desired spatial position. Since this supporting device uses the electromagnet to restrain the rotative movement of the polyarticulated arm, the supporting device itself becomes not only expensive, but also running cost rises because the electromagnet must continue to be energized to fixedly support the medical equipment, except when the medical equipment is moved.